V6 Head Gaskets??Misfires

[321Away]

Anyone had experiences with V6's doing head gaskets? got 1 in that starts and runs but wont rev over 4000rpm when warms up the misfires becomes worse and wont rev over 2000rpm, have replaced distributor cap, rotor arm and leads, next point is to swap out an air flow sensor (the car doesnt show any fault codes?). Just wondering if anyone else has bumped into this before i start pulling off bits. Seems to be some pressure building in the header tank too

Julian

[Simon Jones]

A few misfire related threads that might help:

http://www.igmaynard.co.uk/bongo/forum/ ... v6+misfire
http://www.igmaynard.co.uk/bongo/forum/ ... v6+misfire
http://www.igmaynard.co.uk/bongo/forum/ ... re#p531730
http://www.igmaynard.co.uk/bongo/forum/ ... v6+igniter
http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=53160

I guess there are 3 main areas to check: air, fuel & ignition. The most common problems seem to be ignition-related e.g. HT leads, plugs, coil / igniter. Several problems also related to oil & water around the plugs leading to HT tracking.

Are you getting other symptoms such as white smoke that might point towards a head gasket issue? You can figure out which side or cylinder is affected by disconnecting each HT lead in turn. Our Golf GTi seems to pop a coil pack at least once a year so I just disconnect the LT leads going in to identify which one is at fault.

Also, try running it with the petrol filler cap partially undone. When I undo mine I get a noticable 'whoosh' of air, but it seems to be positive pressure rather than a vacuum which I what I would have thought was more likely.

[Northern Bongolow]

pipe sucking flat ???, gets worse as the pipe gets warm ???,